Nozzle-head for a water-cooled blowing lance

ABSTRACT

The invention relates to a nozzle-head for a water-cooled blowing lance comprising at least one outlet opening for a gaseous refining agent and, if desired, fine-grained fluxes, an inlet piece, at least one nozzle tube leading through a watercooled space and a front plate to which the at least one nozzle tube is connected, in which the improvement resides in that both the inlet piece and the front plate are provided with tubular projections which are connected with each other to form said nozzle tubes, the connection plane lying perpendicularly to the nozzle-head axis at a distance from the front plate amounting to about one-fourth to two-thirds of the height of the nozzle-head. The number of connecting seams corresponds to the number of nozzle tubes; the seams are far away from the front plate and thus sheltered from any danger to damage.

ilnited States Patent Schweng et al. Aug. 7, 1973 [54] NOZZLE-HEAD FOR A WATER-COOLED 3,680,785 8/l972 Miller 239/1323 BLOWING LANCE 3,065,916 11/1962 Kurzinski 239/1323 3,430,939 3/1969 Berry 239 1323 x [75] Inventors: Otto Schweng,Hellmuth j Halls Karl Primary ExaminerM. Henson Wood, Jr. Eicher, all of Linz, Austria Assistant Examiner-Michael Mar [73] Assignee: Vereinigte Osterreichische Eisen-und Atmmey Kun Kama" itglltllwsrke Aktiengesellschaft, Lmz, ABSTRACT The invention relates to a nozzle-head for a water- [221 plied: 1971 cooled blowing lance comprising at least one outlet [21] Appl 202,702 opening for a gaseous refining agent and, if desired, fine-grained fluxes, an inlet piece, at least one nozzle Related Apphcano" Data tube leading through a water-cooled space and a front [62] Division of Ser. No. 61,090, Aug. 5, 1970, Pat. No. plate to which the at least one nozzle tube is connected, 3,662,447- in which the improvement resides in that both the inlet piece and the front plate are provided with tubular pro- [52] US. Cl. 239/1313, 29/481 jections which are connected with each other to form [51] Int. C1 1305b said nozzle tubes the connection plane lying e -pen- [58] Field Of Search 1 132.3; clicularly to the nozzle-head axis at a distahce from the 29/157 481 front plate amounting to about one-fourth to two-thirds of the height of the nozzle-head. The number of conl 1 References Cited necting seams corresponds to the number of nozzle UNITED STATES PATENTS tubes; the seams are far away from the front plate and 3,322,348 5/1967 Vonnemann 239 1323 thus Sheltered from any danger to damage 2,807,506 9/1957 -Gehring .1 239/1323 2 Claims, 8 Drawing Figures 3,387,838 6/1968 Dortenzo et al. 239/1323 X 1 PAIENIEU AUB SHEET 2 0F 2 NOZZLE-HEAD FOR A WATER-COOLED BLOWING LANCE This is a division of application Ser. No. 61,090, filed Aug. 5, l9'70 now US. Pat. No. 3,662,447.

The invention relates to a nozzle-head for a watercooled blowing lance comprising one or several outlet openings for a gaseous refining agent and, if desired, fine-grained admixtures, an inlet piece, one or several nozzle tubes leading through a water-cooled space and connected with a front plate.

In basic oxygen steelmaking methods the oxygen necessary for refining the pig iron is blown onto the metal bath by means of water-cooled blowing lances. These blowing lances are provided at their lower end with nozzle-heads usually made of oxygen-free electrolyte copper which guarantees a long life of the nozzle'head because of the good heat conductivity and the poor affinity of copper to oxygen.

In the course of the development of basic oxygen methods at first blowing lances with only a single outlet for oxygen and, if desired, fine-grained fluxes were used. As a rule, the blowing lances comprised an oxygen supply tube and a nozzle-head, the outlet opening in the nozzle-head being preferably designed to be converging-diverging (Laval-nozzle). The nozzle-heads were produced from preforged blanks by chip removal. Later on, nozzle-heads with several outlets, so-called multi-hole nozzles, were used for larger converters; in this type of nozzles the holes are arranged in a manner that their axes are inclined to the blowing lance axis under a specific angle and the refining agent leaves these holes in several streams so that the reaction area of the oxygen with the melt is enlarged. Today, for most basic oxygen converters multi-hole nozzles are used which have e.g., three, four, five or six outlet openings. At first the nozzle-heads for such blowing lances were manufactured exactly as those for the one-hole nozzles. It was found, however, that this manufacturing process was unsuitable because the medium part of the nozzlehead, the so-called star, is greatly worn as a result ofinsufficient cooling, which may lead to a leakage and an unfavourable blowing performance which again causes slopping of slag and metal from the converter and a higher nitrogen content of the steel. It was realized that the nozzle-heads, which so far had been made of one piece, had to be divided into several individual parts; these parts are produced separately and then connected with each other by soldering or welding so as to permit access of the cooling water to the individual nozzle tubes. The individual parts are primarily produced by forging so that a fine-granular structure is present in the material; cast parts have a coarse and porous structure and are unsuitable for this application. In the method employed so far e.g., for the production of a three-hole nozzle, an inlet piece and a front plate are separately manufactured by drop forging whereupon these parts are worked by means of chip removal and connected with each other via three interposed prefabricated nozzle-tubes by soldering or welding. This way of manufacturing necessitates exact working and fitting of the individual parts, soldering or welding is very time consuming, and great manual dexterity is needed because it is difficult to connect the nozzle tubes, which are arranged very closely side by side, with the front plate and the inlet piece. The life of the multi-hole nozzlesthus produced was improved but still it may happen that the nozzle-heads are ruined prematurely owing to unavoidable faults in the manufacturing process. A particular disadvantage resides in that two partition planes are present in that part of the nozzlehead which gets into contact with oxygen; of these planes one lies very closely to the surface of the front plate. In case of flame erosion of the nozzle-head in the vicinity of the outlet openings it may happen that the soldering seam of this partition plane gets undone which would result in a failure of the nozzle-head.

The invention is aimed at creating a new nozzle-head for oxygen blowing lances with one or several outlet openings with which these disadvantages and difficulties are avoided.

In a nozzle-head of the kind defined in the introduction the invention resides in that both the inlet piece and the front plate are provided with tubular projections which are connected with each other to form nozzle tubes, the connection plane lying perpendicularly to the nozzle-head axis in a distance from the front plate amounting to about one-fourth to two-thirds, preferably to about one-third, of the height of the nozzle-head.

A water deflecting body is resting on ribs of the front plate, said body being provided with recesses whose number and shape corresponds to the number and shape of the nozzle tubes, the walls: of said recesses surrounding the nozzle tubes for at least two-thirds of their circumference thus forming continuous annular cooling-water canals.

The annular water deflection body may be composed of two parts. a

In order that the invention may be more fully understood'these and further features of the invention shall now be explained by reference to the accompanying drawings.

FIG. 1 a is a vertical sectional view of a nozzle-head connected with a blowing lance according to the known construction and manufacturing technique, which was also employed by applicants so far.

FIG. 1 b is a horizontal sectional view along line II of FIG. 1 a.

FIG. 2 a is a vertical sectional view of the nozzle-head according to the invention and FIG. 2 b is a horizontal sectional view along line [1-11 of FIG. 2 a.

FIGS. 3 a, 3 b and 3 c illustrate the method according to the invention and show vertical'sectional views of theblanks for the inlet piece and the front plate, re spectively, and of the water deflecting body.

FIG. 4 is a vertical sectional view through the blanks for the inlet piece and the front plate which are combined with the help of an auxiliary device according to a specific embodiment of the method according to the invention.

The nozzle tip which belongs to the art and is shown .in FIG. 1 a comprises a nozzle-head l which gets into contact with the refining agent, and comprises a water deflecting ring 2 forming a separate constructional part which guides the cooling water to the nozzle-head l. The nozzle-head 1 comprises an inletpiecefi, three individual nozzle tubes 4 and the front plate 5 which parts are rigidlyconnected with each other by soldering or welding. The axes of the nozzle tubes 4 are inclined towards the vertical line. In the water deflecting ring 2 recesses 6 are provided; annular canals are formed between the walls of these recesses and the nozzle tubes 4 through which canals cooling water flows with high speed in the direction shown by the arrows in FIG. I a,

i.e., in downward direction toward the front plate 5. The individual parts 3, 4, 5 of the nozzle-head 1 are connected with each other at six junctures (there are three junctures at 7 and three at 8); the three junctures 7 lie in planes close to the surface of the front plate 5 and therefore they are in great danger when the nozzlehead is used in a converter. As may be seen from FIG. 1 a it is extremely difficult to solder or weld the conical nozzle tubes 4 which have to be very closely spaced to the front plate 5 and the inlet piece 3 so as to have a leak-proof connection all around. The nozzle-head l is welded or soldered via its inlet piece 3 to the oxygen tube 9 of the blowing lance and via its front plate 5 with the jacket tube 11. Between the tubes 9 and 11 a water guiding tube is built in which is rigidly connected with the water deflecting ring 2 which is supported on ribs of the front plate 5 so that the front plate is intensively cooled, too. Particularly endangered zones of the front plate 5 are the middle part (star) denoted with numeral 12 and the edges 13 in the area of the outlet openings 14 for the oxygen.

FIG. 2 a shows for ready comparison the nozzle-head according to the invention. The nozzle-head 1 comprises only two parts, i.e., the inlet piece 3' with tubular projections 17 and a front plate 5 with tubular projections 16; thus, only three junctures 18 are present which are at a great distance from the surface of the front plate 5 and are lying in one plane, which is perpendicular to the axis 33 of the nozzle-head. This connection cannot come undone owing to the influence of heat because the connecting areas are in about the middle of the nozzle-head 1. It is suitable to arrange the planes of the junctures 18 at a distance from the surface of the front plate 5' amounting to from one-fourth to one-third of the height of the nozzle-head l. The ring 2 around which the water circulates is provided with recesses 6' surrounding the tubes 16 through about two-thirds of their circumference, thus forming continuous annular canals; in FIG. 2 a the current of the water is illustrated by arrows. The speed with which the water circulates through the nozzle-head is continuously increased in the area of the ring 2' to reach a maximum when the water enters the space defined by the tubes 10, 11. The baffle ring 2' rests on narrow ribs 15' (FIG. 2 b). Preferably the ring 2 consists of one piece. In the area of the inlet piece 3 a groove or notch 20 is provided for engaging adjusting screws 19 for centering the water guiding tube 10 relative to the oxygen tube 9.

FIG. 3 a shows a blank 21 for the inlet piece 3 which blank is drop forged from a preformed block in one or two heats. The blank 21 is provided with three conical studs 22 whose outer shape corresponds to the tubular projections 17. FIG. 3c shows a blank for the front plate 5', which blank 25 is formed in the die from a block which is preformed in one or two heats; in this process a five to 25 fold total shaping is to take place; a preferably 10 to 15 fold shaping is necessary in order to obtain a fine-granular and dense structure. The blanks 21, 25 are preferably made of oxygen-free electrolyte copper. In principle, it is, however, possible to use also other metals, e.g., pure nickle or stainless steel for producing them. The blanks 21, 25 have an outer shape which makes it possible to form the necessary bevel edges 24, 24 and the groove 20 for connecting the nozzle-head with the blowing lance and for engagement of the adjustment screws 19, respectively, at a later point. In FIGS. 3 a and 3 c the inner contours of the tubular projections 16, 17 is shown in dotted lines. After forging, at the ends of the studs 22, 26, planar surfaces 28, 28 are produced which are perpendicular to the axis 33 of the nozzle-head, and central holes 23, 23' are'driven in, so that bores 29 (FIG. 4) may be produced going through the studs 22, 26. In FIG. 3 b the water deflecting ring 2', which is preferably made of steel in one piece, is shown. This ring 2' lies on the supporting surfaces 27 (FIG. 3 c) of the ribs 15' of the front plate 5' when the nozzle-head is joined to the blowing lance.

FIG. 4 shows an auxiliary device for joining the blanks 21, 25 which device comprises a plate 30 and vertically arranged guiding pins 32. Previously, holes 29 had been bored into the blanks through the studs 22, 26 within the predetermined inner contour of the tubular projections 17, 16, which is shown in dotted lines. The guiding pins 32 engage in these holes 29 and represent a centering means for the blanks 25, 21. Between the partition planes 28, 28' a solder in the form of an annular solder foil is inserted, whereupon heating to soldering temperature of about 700 to 900 C in a temperature controlled furnace takes place. Then the blanks are cooled slowly to obtain a firm soldering connection between the blanks 21, 25. If, as shown in FIG. 4, a water circulating ring 2' is used made of one piece, it is inserted after the blank 21 is put onto the auxiliary device comprising the plate 30 and the guiding pins 32 whereupon the blank 25 is joined with the blank 21. After the blanks 21, 25 are soldered, the auxiliary means is removed and mechanical working is started, i.e., the milling or boring, respectively, of the insides of the tubular projections 16, 17, the bevel edges 24, 24', the groove 20 and the support planes 27 (FIG. 3 a or 3 c, respectively). The finished nozzle-head 1' together with the water circulating ring may then be welded with the tubes 9, 10, 11 of the blowing lance; adjusting screws 19 help to carry out centering of the tube 10.

What we claim is:

1. In a nozzle head for a water-cooled blowing lance, comprising at least one outlet opening for a gaseous refining agent, an inlet piece, at least one nozzle tube leading through a water-cooled space, a front plate to which each said nozzle tube is connected, the front plate having ribs, a water deflecting body supported on the ribs of the front plate, said body being provided with recesses whose number and shape correspond to the number and shape of the nozzle tubes, the walls of said recesses surrounding the nozzle tubes for at least two-thirds of their circumference, thus forming continuous annular cooling-water canals, and the inlet piece and the front plate having tubular projections connected with each other to form said nozzle tube, the connection plane lying perpendicularly to the nozzle head axis at a distance from the front plate amounting to about one-fourth to two-thirds of the height of the nozzle head.

2. The nozzle-head set forth in claim 1, wherein the connection plane is at a distance from the front plate amounting to one-third of the height of the nozzlehead.

4 Patent No. 3, 750, 952,

UNITED STA E-Si PATENT OFFICE 1 I I cER mcmtgw @Q'EGTIGN t,

Dated A11 7, 1973 lr ivent fl Otto Schwenqet a1 It is certified that error appears in the above-identified patent 5 and that said Letters Patent are hereby corrected as shown below:

In the heading, between the entirtgs" {62) and {52?3 insert:-- t

(30) Foreign 'ApplicatzlonPrioztity Data Au 14, 1969 Austria 0 o a a A 7830/69 Signed and sealed. this 8th day oftOctober 197 Attest:

MCCOY M. GIBSON JR. co MARSHALL DANN Commissioner of Patents 1 Attesting Officer uscoMM-Dc scam-Pad U.S. GOVERNMENT PRINTING OFFICE I I955 0*355'35.

FoRMfPo-mso (10-69) 

1. In a nozzle head for a water-cooled blowing lance, comprising at least one outlet opening for a gaseous refining agent, an inlet piece, at least one nozzle tube leading through a watercooled space, a front plate to which each said nozzle tube is connected, the front plate having ribs, a water deflecting body supported on the ribs of the front plate, said body being provided with recesses whose number and shape correspond to the number and shape of the nozzle tubes, the walls of said recesses surrounding the nozzle tubes for at least two-thirds of their circumference, thus forming continuous annular cooling-water canals, and the inlet piece and the front plate having tubular projections connected with each other to form said nozzle tube, the connection plane lying perpendicularly to the nozzle head axis at a distance from the front plate amounting to about onefourth to two-thirds of the height of the nozzle head.
 2. The nozzle-head set forth in claim 1, wherein the connection plane is at a distance from the front plate amounting to one-third of the height of the nozzle-head. 